Nail coverings and methods of making same



Aprll l1, 1961 J. GREENMAN ETA'. 2,979,061

NAIL covERINGs AND METHODS oF MAKING SAME Filed Aug. 2, 1957 |NvENToRs Joseph g/eenman Paul Sha a Thomas Tavern/ BY Poca/ Coke/Z ATTORNEYS @252301-200 z wm Harrison, N.Y., assignors to Technical Tape Corporation, Bronx, NX.

Filed Aug. 2, 1957, Ser. No.675,9'39 1sA claims. `(ci. 13a-1s) This invention relates to plastic articles useful inpro- 'viding decorative coverings for human iingernails and toenails as well as, to methods of making ,suchsarticles Articles of this general nature are described in United States Patent 2,688,331 to Bogoslowsky; howeveras this specification proceeds it willbe apparent that.embodi` ments of the present invention are significantly different from the articles described in the said patent.

Conventionally, vhuman nails are brush coated with lacquers, either clear or colored, dispersed in volatile solvents. However the operation of coating the nails is slow and tedious, the lacquers tend to break and crack thus exposing the fingernail; furthermorel the consistency and quality of a given bottle of nail lacquer deteriorates rapidly once the ybottle has been opened.

The object of the present invention is to overcome the ditculties and disadvantages of known articles andfmethods of coating nails and to provide an article which may be appliedto nails by an inexperienced user rapidly, ei ciently and at^fmodest cost.v It isa further object .of the invention to provide fngernailblankswhich will adhere f 'tenaciously' to the nailsofthe user for extended periods of'time, which are nonallergenic ,fwhih arehighly decorative, which are easily and simply removable" and whichcan-be made rapidly and precisely in commercially feasible operations, Other objectsor'V they invention will be apparent as the speciicationgproceeds. l

In accordance with the inventionthereis lprovided a s thin, highly yiiexible, abrasionV resistant ngerna'il `blank completely4 coated on-one sidewith aH high vadhesive strength, non-allergenic, .pressure-sensitive adhesivewhich` is` highly tacky', highly cohesive, resistant "bothto heat and to cold flow andwhich" has ahighs'hear'strengthllf.

rhe,adhesive side of the blank is' attachedv to a` supporte v ing carrier sheetwhichisof a typ'efthat `readily releases 1i theadhesivejwithout adhesiveoisetting rtransferan'd' .withoutidistort'ion of the thin ",tingernailio'r toeriail blank.

Perhaps" the features of the invention' can best be ppreciated and described by-referringfto specific embodimentsthereof and the accipanying'drawings wherein:

2Figurerlis'fperspectivev view of a nail blankV accord- 4 ving tn theinvention, cross-sectionalgview `takerralong the "i yFigii'fefS is, a diagrammatic shieetzof agi-method blankassembly 1-2 which s; compr`is ed of a plurality of ,thin il'e'rible slieet's,4 or. .membersg 14 the" outerv edges s A14fa,c )f 4which conform'. to s the contours; of `Vthe inner porytioirsgf vea'clrof 'the' human' nails. The sheetsf\14 are supported by 'acarrier sheet 16j-which iseiible, ybut may I p s ;iieXifble-thamthejfnail blanks,V 14, lThe assembly l A. I of 'he assembly, prciyides' ,71separateinailsmembers and providesi ,5'A membersi-in `accvor'danc'e 'with' v'the set forth in vthe coepending applicatie' et'v Jaul.4

, seriali NQ.-,672 ,31o,. ined-1 Julyv 16,4957? ,L f1

,Y 2,979,051 f Patented Apr.- 11,1961

Referring to Figure 2 it will be seen that slit or" cut 18 in members 14 does not extend/through carriersh'eet 16; As shown, .members -14 are coated on the underside with Apressure-sensitive''adhesive 17 for their entire width. Narrow lift sheets 22. of'ftl'exibleV material such as triacetate underlie members-14 along each side of the center slit line 18; sheets 22; are held in place on their upper sides by the pressure-sensitive adhesive layer`17 and on their lower sides-by the separate, lighttack pressure-'sensitive adhesivei24.- This arrangement,` as will be pointed out below, provides lblanks which are readily removable lby'theuser and which'may be manufactured in a practi-V caly and etlicient mannen Figure 3 illustrates diagrammatically a method-of produeing fingernailblanksaccordingA to one aspect of the invention; First, a 95 %5 vinyl chloride-polyvinyl acetate copolymer'resn is mixed with'suitableY stabilizers,

anti-oxidants, pigment dispersion aids, iillers, color pigf ments and plasticizers. For example, a 95'-5 vinyl chlo ride resin is mixed inv the proportionsof aboutY 100 parts by weight of resin 4and 35-part`s by weight of' a non-mn grating resinous plasticizersuch as the polymeric ester resin sold by Bakelite Division of Union Carbide Corporation, NewYork, VNew York, under its designation of Flexol R 2H; other similarvplasticizers may also beused suchv as'the polymeric esters of a low' molecular weight glycol anda dibasic acid such as sebacic acid made and sold bylohm and Haas, f Philadelphia,` Pennsylvania under its designations Paraplex G-25, G-40, G-SOor G*- 60,v Y In other instancesfmononreric plasticiz'ers such as tricresyl phosphate'or dioctylphthalate ori the like maybe substituted in part for the wholly resinou's plasticizers indicated above. The resin is to be used so that the elasticity of the compoundedyinylilm isbetween about 125% to .about 300%. Thereafter. the compounded resin is calendared to a sheet form or film of at least 21/2 mils to 51/2 mils thickness, and preferably 4%. mils thickness.l The calendared iilm is formed so' Vthat one; side is dull or matte in finish, this side later- Yreceiving the pressure-sensitive adhesive. layer 17. "The opposite side ofthel elastic lm is made highly glossy by calendaringand 'press' polishing (While the "lm is at'elevated temperature) on polishedrolls, or, alternativelyisprinted rolls, one being rubber coated and the other a heated,

^ 'highly polishedy nish roll, Vpreferalily chromium plated.

It istdbe notedthat a highly glossy tlm (described be# low) is simultaneously passedv betweenrthe nip ofthepolishingrollers and in directv contact with `the chrome surfaced roller. "While smoothcellophan'e, polyesterilm or metal foils maybe used, .advantageouslyv 2 mil thick elluloseacetate film, which 'is'V fairly stii,"is used. This 'f acetate lm "serves to 'convey the'vinyl'iilii (whichis quite distortble; especially when heated;A and Aalso to ifn parta glossof abouti ona standard "glossometerto the-,vinyl vilnr by direce YContact thereto.

, In accordance @with a` ,presently rpreferredl-proceduref by=aseparate operation polyethylene filmsv (which .aretol servevas carrier sheetsin the'iinished product) iare'simi-Y larly press polished sothatf fthe polyethyleneleal-rien n sheetsare` given ahighlysglossy sufa'ce on' onesidei and.V amore orfless Arnattefiinish on the' bl'apo'sitetside;I 'The; 'glossyisideof the polyethylene sheets willbe ,th'e'fund'erf i.

adhesion betweenseparate 'blanks wliile'"`a'djacent toene'Y another,l aspect of theinvention the'kacetate care rier sheet may be wound out and the polyethylene film` carrier wound in after press polishing. Alternatively, the acetate carrier may be used to convey the polished vinyl film through the subsequent steps of priming and coating. Y p

It is to be noted that the compounded polyvinyl chloride-acetate lm described is highly fiexible, water resistant and abrasion resistant. It is also glossy and may be compounded in a wide variety of attractive colors. In some instances other films may be used such as polyethylene which, however, is somewhat deficient compared to vinyl films in that the polyethylene films have less abrasion resistance, less elastic recovery and may tend to curl and lift ofi a womans fingernail. Similarly, cellulose acetate, metal foils, the polyester film known as mylar and laminates of those materials with one another or with vinyl lilm or cellophane may be used. In each instance such films or laminates will be stiffer and less flexible than the vinyl films, which is less desirable. However, polyethylene films and mylar films do not require plasticizing and in this respect are advantageous.

In compounding the various films for the nail sheets 14, the use of lead or asenical compounds or similar allergenic materials is to be avoided. p

Continuing now with the description of the vinyl film specified above, it is next prime coated on the dull or matte surface by use of a doctor knife blade, or squeeze or nip rolls or by transfer printing. t The primer composition is applied either as an aqueous emulsion or dispersed in a solvent, the viscosity and amount of primer coated on the film being adjusted so that a wet film only 1A to 1/z mil is coated on the film. The primer is then air dried at about 180 F. The composition of the primer Vis significant. The following compositions achieve excellent results and avoid offsetting with the high tack, high cohesive strength adhesives which are to be used.

Primer Example 1 Parts by Total Solids,

Weight Percent Butadlene-acrylonltrlle elastomer, as nqueous emulsion 37. 5 38 High styrene-but adiene polymer. as aqueous emulsion (e.g. 70% styrene-30% i butadiene polymer) 12. 5 34 Neoprene Latex (e.g. 842A of du Pont), Le.

a chloropreuel from E. I. du Pont de Nemeurs. Wilmington, Delaware I10.0 30 Aqueous emulsion of pentaerythrltol` esters of hydrogenated rosin 150. 40

The above aqueous emulsions are mixed slowly while stirring to avoid breaking of the mixed emulsions. l

Primer Example 2 `Pai-ts by Total Solids,

'Weight Percent A Heptane 50 Polyacrylate resininmfneral thnnerleg. t an acrylate resin such as Acrylold F10,`

a synthetic polymerized` acrylic acid ester available from Rhm und Haas. Phila i adelphia,4 Pa ,100 40 heet resistant. 10mm@tf1@wfrnotl-a11eggenie;rapid. y.anna-.

60 1" (as 25% solution in heptane) ence, pressure-sensitive adhesive (hereinafter referred to as a hyperpressure-sensitive adhesive) to the primed side of the vinyl film. Inasmuch. as the fingernail blanks are to be decorative, adhesive oozing to the extent found in 5 conventional pressure-sensitive adhesive tapes is quite disadvantageous; also the blanks are to withstand the users washing her` hands in hot dishwater containing strong detergents and other materials. Thus a tackiness of about 80-100 ounces per inch width (measured by a draw down adhesion test on a standard stainless steel test panel) is needed in contrast to the typical 50-60 or so ounces of tack `in a conventional pressure-sensitive adhesive used on cellophane tape. Examples of usable hyperpressure-sencitive adhesives having the requisite characteristics for the objects of this invention are given below.

. Adhesive Example l Ingredient: Parts by weight Natural rubber (pale crepe) 97.1

Butadiene-styrene synthetic lrubber' (GR-S 1011) t Y `97.1 Anti-oxidant 5.8

Peutaerythrtol ester of hydrogenated rosin 125 Thermoplastic terpene resin (M.P. 85 C.

app.) 92.6 Heptane 150 Hexane 60 The amount of solvents in the above adhesive example may be varied to yield a `total solids content of approximately 25%.

Adhesive Example II 3 Ingredient: Parts by weight Natural rubber (pale crepe) 137 Silica reinforcing pigment 39.2

Zinc` oxide pigment 27.5

Anti-oxidant 4.1

Pentaerythritol ester of hydrogenated rosin 168 Plasticizer (e.g. low molecular weight polyisobutylene) 14 Vulcanizing agent (e.g.` sulfur containing phenolic resin such as Vultac #3, from Sharples Chemical Co., Philadelphia, Pa.) 4 `Hexane u 90 i Heptane ,30

In the preceding adhesive composition therubbcr, pigment and anti-oxidant components are first dispersed 'in about 75 `gallons 'of the hexane-heptane solvent; to this is added the remaining ingredients which havebeen pre-'dispersed in a 'hexane-heptane solvent. The total solids 'content is maintained at about 36%, yielding a viscosity fof betweenV 40,000 and 50,000 centipoises.

a f `Adhesive Example III l, Ingredient: l Parts by weight High molecular .weight polyvinyl ethyl ,etherv ..--.l 222 Low molecular weight lpolyvinyl ethyl ether ..-u 16.7 Hard, brittle polyme'rized` rosin' (M.P. app.V

Azow-211" E.) i.; 16.7 Soft A`diethylene" glycol ester vof hydrogenated rosin j'l Q l `A Br'ittle," hard, low`` acid number(M.P. 100 C."

i app.) resinified alpha pinene '16.71,

Upon completion 'of the adhesive coating step, the;

laminated'sheet of acetate carrier a'nd adhesive ,u coatedvinyl film is'next dried,1avoidi`ng' tempratures which `will curl orwrinkle the exible vinyl lm." t It is noted that a"l significant amount of shrinkage ofthecalenda'red film occurs. in` the drying steps;- thus minimizing shrinkage in" the final fingernail blanks and-:insuringfreedonfrm film the required lustre.

After completionfof the adhesivecoatingand drying steps, theacetate-carrier4 sheet is wound out (for re-use if desired) and1lift sheets 22, bearing a mildly tacky pressureasensitive adhesive24 are inserted at pre-determined vdistances acrossthe width of the vinyl sheet. vSuch liftr sheetsare advantageouslyl made of a, white pigmented sheet ofv cellulose triacetate, approximately l mil thick; such lift sheets facilitatetheremovalof anindividual blank14 by the user.

In a-presently preferred procedure, 12'lift sheets'eahv lfwide are adhesively` attachedI to the vinyl film per 30 of'width of the film. It is of importance thatv the attachment of the lift sheets be accomplished shortly be-v foreslitting because of-theshrinkage of the film in the priorfstepsand because of the diiculty in winding up the film precisely. Otherwise stated, the filmmay tendto creepdue to shrinkage and transportof the lm, so thats the .lift sheets, if attachedprematurely, willfwalk and s not remain precisely aligned, as isrfneeded in theA subsequent slitting. l

Upon attachment of the lift sheets, they are promptlyv slit down the center thereof and thereupon the permanent carrier.v sheets (preferably of press-polished polyethylene film as heretofore described) are wound into the film. Next-the'larninated sheet comprised of vinyl film, lift sheets and carrier sheets is slit into small sizerolls (eg.V about 6"-7" wide) which are next die cut into the 12 blank padsk shown in Figure 1, atwhich point they are ready for packaging in the form so-ld to the user. Y

It is of importance that the adhesion of the thin distortable fingernail blank to the permanent release sheet beccomparatively low. As noted above the hyperpressure-sensitive adhesives usedexhibit tackiness to standard stainless lsteel-panels of the ordervof 80v ounces per inch. At. the same time thek vinyl film, as applied'to theusers fingernails is a thin, elastic film` with minimum internal -r stresses so that creep or curl on ythe fingernails is avoided. Inremovingthe blanks from the releaseor carrier sheet,

itisimportant that 'the act of removal; not distortthe `film so that undue stresses are set up in the film. To acstabilizers and anti-oxidants similar in kind and quantity to those used in making the calendared film described above. v The organosol is then flowed onto a carrier sheet adapted for forming the'organosol into a cast vinyl film and then conveying the cast film through the subsequent operations. v v

AThe carrier sheet used' with organosols differs from that used in makingv calendared film.v Preferably there is used a dense, glossy'surfacedrpaper suchV as 55 to 90 VKpound machine finished or glazed kraft paper, although plastic sheets and the like may be used provided the surfaces ythereof are suiciently glossy to impart to the vinyl sheetiscomprised of a combination of a tough thermO setting resin, anfalkydresin tofacilitatethe continuity (orfilmv formingy ability) of the, coating; and wax-like materials which are repellent to, pressurefsensitive ad-y hesives--all dissolved, inV suitable,l solvents. Excellent results have been attained by the4 use of a Acomposition containing approximately 15% waxyv amides derived from fattyv acid such as A rmidl C andrArmid 8 from Armour and Co., Chicago, Illinois, whicharel essentially derived from C10 and C9 fatty acids'respectively,` 121/2'% alkyd resin, lll/2% thermosetting Vurea-formaldehyde resin,- 1/2% n-butyl phosphoric acid andthe; balance a mixed solvent of y isopropanol and methylisobutyl ketone (there being about 7 parts isopropanolto 1 part of ketone).

The organosol is cast onto'the vinyl release coatingi side of the coated-carrier sheet and the solventA evap- Such carrier sheet is first processed on each side to perform vseparate functions. JTo

fr one side-ofthev carrier sheet there is applied `a vinylrellease vcoatingwhich is'to impart lustre to the filmand also to permit its removal, withoutsubstantial distortion,

when the-,film is ultimately removed from'the carrier. .-The'opp'o'site side of the'carrier sheet is coated with a. "'.vpressure-sensitive ,adhesive releasecoat, ofthe type de-v scribed below. j Y A The ,adhesiveV release coating appliedzto the'jcarrier" orated from the organosol so that a dried 'vinyl film of about 41/2 mils thickness is formed. Thereupon the vinyl filmfon its carrier is coated first with a primer as described above, dried and thenadhesive coated with a hyperpressure-sensitive adhesive in accordance with the foregoing examples.

After drying of the adhesive coating, the paper carrier sheetis wound out, lift sheets attached as described in the use of calendared film (i.e. with mildt pressure-seusitive adhesives of less than l0 ounces tack), initial slitting conducted and the permanent carrier sheet Wound in. As indicated heretofore the permanent carrier sheetmay be polyethylene, glassine or parchment paper or papercoated with silicone, alkyd urea, andthe'like which will Ashown in Figure l. Y .l

Having'fnow particularly ,described-embodiments of our invention' what is claimed is:l l f v1. Al fingernail lblank. which., comprises aV first sheet of` thin flexible extensible sheetof a.copolymerfof vinylt chloride and vinyl acetate highly plasticized with a nonexuding plasticizer, said first sheet being pre-cut to form a plurality of members adapted to conform to the curvature of the cuticles of human fingernails, each of said members having adhesively attached to the underside of its innermost edge a lift sheet, said first sheet being highly glossy on one side thereof, the opposite side of said first sheet being covered with a hyperpressuresensitive adhesive composition, the tackiness of said adhesive to a standard panel beingat least ounces per flinch, saidfirst sheet being supported by a relatively stiffer -car'riertrelease sheet in direct contact with said adhesive, I

said hyperpressure-sensitive adhesive is comprised of a tackifying resin and a tackifiable rubbery elastomer, the ratio of resin to elastomer being between about 1.1:1

and 1.3 to 1.

3. A fingernail lblank according to claim 1 wherein an adhesive primer coating lies between said first sheet and said adhesive, said primer having a high specific attractionto hydrophobic films.k

4. A fingernail blank according to.y claiml 3 wherein said primeriscomprised ofrtackiable synthetic rubbery elastoniers mixed with a tackifying esterifiedv resin,l the 6. Themethod of kmaking a fingernail ,blank which comprises supporting athin fiexible glossy film on a relatively Istiffer carrier sheet, thereafter successively apf I 1 plying and dryingan adhesive priming coat and a'hyperpressure-sensitive adhesive coating, to onelsideofsaid film, removing said carrier sheet, next applying lift sheets at pre-determined spaced intervals to the adhesive coated side of said film, next applying a permanent carrier sheet to said adhesive coated side of said film, the side of said permanent carrier sheet in contact with said adhesive being weakly attractive to said adhesive, and thereafter slitting and cutting said composite sheet and film to provide a plurality of members adapted to conform to the curvature of the cuticle portions of fingernails.

7. The method of making a fingernail blank which comprises casting a polyvinyl organosol onto a glossy supporting sheet, said glossy supporting sheet being coated on the side thereof in contact with said organosol with a vinyl release coating and being coated on the opposite side with a pressure-sensitive adhesive release coating, next drying said organosol to produce a thin flexible extensible vinyl film on said supporting sheet, next applying an adhesive primer to said film, drying said primer, applying a hyperpressure-senstive adhesive to the primed side of said film, drying said adhesive, next winding out said supporting sheet and Vwinding in a permanent carrier sheet, the side of said permanent carrier in contact with said adhesive being weakly attractive to said adhesive, and thereafter slitting andfcutting said composite sheet and film to provide a plurality of members adapted to conform to the curvature of the cuticle portions of fingernails.

8. A fingernail blank which comprises a first sheet of thin exible material having a glossy surface on one side and being coated on the opposite side with a hyperpressure-sensitive adhesive, said sheet being pre-cut to provide a plurality of members adapted to be applied to human fingernails, each of said members having adhesively attached to the underside of its innermost edge a lift sheet, and a carrier release sheet contacting the adhesive coated side of the first sheet, said hyperpressuresensitive adhesive having a tackiness to a standard panel of at least 80 ounces per inch, and an adherence to said carrier sheet of less than 25 ounces per inch.

9. A fingernail blank which comprises a first sheet of thin flexible extensible resilient material having a glossy surface on one side and being coated on the opposite side with a hyperpressure-sensitive adhesive, said sheet being pre-cut to provide a plurality of members adapted to Abe applied to human fingernails, each of said membersA having adhesively attached to the underside of its innermost edge a lift sheet having on the underside thereof a mildly tacky pressure-sensitive adhesive, and a carrier release sheet supporting said first sheet, said hyperpressure-sensitive adhesive on said first sheet and said mildly tacky pressure-sensitive adhesive on said lift sheet being in contact with said carrier release sheet, said hyperpressure-sensitive adhesive having a tackiness to a standard panel of at least 8O ounces per inch, and an adherence to said carrier release sheet of less than 25 ounces per inch. l

i 10. A fingernail blank according to claim 9 wherein said resilient material is comprised of a plasticized copolymer of vinyl chloride and vinyl acetate.

11. A fingernail blank according to claim 9 wherein s'aid carrier release sheet is comprised of polyethylene.

12. The method according to claim 6 with the additional step of coating said lift sheets on the underside thereof in contact with the carrier sheet with a mildly tacky pressure-sensitive adhesive before applying said lift sheets at predetermined spaced intervals to the adhesive coated side of said film.

13. Method according to claim 6 with the additional steps of calendaring said film by heating and then press polishing said film and, while hot, pressure contacting said film to a glassy carrier sheet such as cellulose acetate.

References Cited in the file of this patent UNITED STATES PATENTS `Doyle Feb. 14, 1956 

